Stbing-tbtjing machine



Gm. N. EINSELE.

STRING THUING MACHINE.

APPLICATION min 1AN.22,191s.

1,385,367; Patented July 26, 1921.

3 SHEETS-SHEET l.

u l g jyl.

G. N. EINSELE.

STRING mums MACHINE.

APPLICATION FILED IAN. 22. 1918. 1,385,367'` Patented' July 26, 1921.

3 SHEEIS-SHEET 3.

IIIIIII which,

.with the UNITED STATESl PATENT OFFICE.

` GEORGE N. EINSELE, 0F CEDAR LAKE, INDIANA.

1 STRING-TRUING MACHINE.

To all whom it may conce/'21:

Be it known that l, Grzonor: N. EINsnLE, a citizen of the Untied States`and a resident of the city of Cedar Lake, county of Lake, and State ofIndiana, have invented certain new., and useful Improvements in String-Truing Machines, of which the following is a specification.

invention relates to a. string truing machine, that is a machinedesigned for use primarily in the truing of gut strings used inconnection with stringed instruments,

In` order to obtain the best results upon a stringed instrument so faras the tonal productions are concerned, it is necessary' that the stringemployed be of uniform diameter from end to end or true, it being theobject of my invention to produce a machine which will be capable ofmechanically cutting or trimming musical instrument'strings with l greatprecision and rapidity.

A further object is the production of a machine of the charactermentioned which will be of durable and economical constructionandefficient in use.

Other objects will appear hereinafter.

The invention consists in the combinations'and arrangements of partshereinafter described and claimed. y

The invention will be best understood by reference to the accompanyingdrawings forming a part of this specification, and in Figure 1 is a sideelevation of a string truing machine embodying the invention,

Fig. 2, a sideelevation of the cutting elementand string holder includedin the construction, the carriage of themachine being shown in section,

Fig. 3, a, front elevation of the same construction seen in Fig. 2,

Fig. 4, a` top plan View of the same construction seen in Figs. 2 and 3,

5, a section taken on line 55 of Fig. 4,

Fig. 6, a section taken on substantially line 6-f-6 of Fig. 5,

Fig. 7 a partiallysectional plan view of the means employed forlclampingand rotating the central portion of the string, the samebeing shown incooperative relation parts of the Amachine seen in Fig. 4, andk Fig, asection taken on substantially line The' preferred form` of constructionas Specification of Letters Patent.

Application med January 22, 191e.

Patented July 26', 19.21. serial No. 213,272.

vframe or bed 10, upon which are mounted bearing members 11 and 12, theformer being rigidlysecured and the'latter a'djustably secured so as topermit of shifting ofthe same to accommodate strings of various lengths,as will be understood as the description proceeds.

Rotatably mounted in the bearing 11 and extending loosely throughbearing 12 is a shaft 13 to which is fixed a pulley 13 adapted to bedriven by a belt 13". Upon shaft 13 are mounted three gears 14, 15 and16 of uniform size, the gear 14 being fixed to said shaft, and the gears15 and 16 being splined on said shaft. Meshing with the gear 14 is apinion 17 fixed to a shaft 18 mounted in bearing 11, said shaft carryingatone end a hook 19 adapted for engagement with one end of the stringacted upon. Meshing with the gear 16 is a pinion 20 to whichl is splineda shaft 21 slidably mounted in bearing 12. The shaft 21 is provided atone end with a hook 22 adapted for engagement with the other end of thestring acted upon. l To the rearward end of shaft 21 is swiveled an endpiece 23 to which is fastened a cord or flexible element 24 which passesaroundachannel pulley 25, carrying at its lower end a weight 26 which isa-dapted toexert a pull upon the shaft 21 to the right, or in adirection which will cause the string arranged in the machine to bestretched taut.A

Mounted for recip'rocatory movement upon the bed or frame 1() is acarriage 27. Above said carriage is arranged an electric motor 28mounted upon a bracket 29, the lower end of which is mounted forvertical adjustment in a guide or post 30 arising from said carriage."Upon one side of bracket 29is provided a lug 31 threaded upon a screw 32which is rotatably mounted upon post 30, the arrangement being such thatvertical adjustment of the motor may be effected through rotation ofsaid screw, as will be readily understood. The upper end of said y ofwhich is provided with radial cutting teeth, as clearly seen in Figs. 1,2 and 3.

` The cutting element 34 is so arranged that when a-string is strungbetween theme11!- bers 19 and 22, the .cutting element will be adaptedto contact therewith in order to trim or true the same. Arrangedradjacent one side of said cutting element is a pair of jaws 35 carryingchannel rollers 36 adapted to embrace the string acted upon between thesame. The jaws 35 are fulcrumed at 37 to a tubular collar 38, one ofsaid jaws being fixed against pivotal movement through fastening of thesame to a second lug, as seen at 39 in Fig. 7. Engaging with therearward ends of said jaws is an arched leaf spring 40, las, best seenin Figs. 7 and 8, which serves to press the movable jawA toward theIstationary one and thus to effect secure clamping of the string engaged.The collar 38 is fixed to a tube 41 which is mounted in a bearing 42arising from carriage 27 .l

' Fixed to tube 41 is a pinion 43 which mesheswith the ear 15, thearrangement being such that wen said gear is rotated, the clamping jaws35 will be revolved and thus serve to rotate the string therewith. Thepinions 17, 20 and 43 are all of the same size and meshing with gears14, 15 and 16 also'all of the same size, as above set forth.

upon rotation of shaft v13, the string arranged in the machine will becaused to rotate at the jaws 35 at. a rate of speed precisely the sameas the speed of rotation at the ends of the string. Thev clamping of thestring bysaid jaws is of sufiicient tension to prevent torsionalyielding or twisting of the string when engaged by the cutting element,it lhaving beenxfound that without this provision, the central portionof the string, duringv the cutting operation, will twist and lag andthen sudden y release or jump with thefresult that a non-uniform oruneven-cut-v ting of the string is secured. Through the use of therevolving jaws arranged in close proximity with the cutting element, theobjection. or trouble just described is effectually'overcome and astring` of true and. uniform thickness produced.

Arising from the carriage 27 directly in front of the cutting element34- is a bracket O r support 44 provided atits upper end withhorizontally disposed plate 45, as clearly seen in Figs. 2,3, 4, 5 and6. Slidably mounted upon plate 45 is a plate 46 adjustable toward andfrom the cutting element by means of a screw 47 provided at itsouter'end with a crank handle 48, the inner end of said screw beingthreaded into a lug 49 depending from the plate 46 through an elongatedslot-50 rovided in plate. 45 as seen 1n Flg. 5.' Slidalb y mounted uponthe upper sideof plate 46 vis a `presser shoe 51, held in position byanother plate 52 screwed to the plate 46, the plate 52 being formed witha channel for the accommodation of said shoe. as clearly seen in' Fig.3. Movement of presser shoe 51 toward and from-the` cutting element iseffected by means of an eccentric 53 operating in a slot 54 provided insaid shoe, asclearly seen in Figs. 5 and 6. The eccentric is carried bya shaft 55 upon the upper end of which is loosely mounted a lever 56.Operative connection between said lever and shaft is effected by meansot an adjustable pawl 57 adapted for engagement with a toothed segment58 fixed to said shaft. The pawl 57 is slidalble upon the underside oflever 56, the same being locked in positions of adjustment by means of athumb nut 59 threaded upon a post 60 arising trom said pawl and passingthrough an elongated slot 61 provided in said plate, as clearly seen inFigs.A 2, 4 and To take up any lost motion between eccentric 53 and thepresser shoe and maintain a constant contact between said eccentric andone end of the slot 54, a leat` spring 62 is provided in said slot whichengages against the eccentric, as clearly seen in Fig. 6.

The arrangement is such, as will be seen, that shifting of the pressershoe toward and from the cutting element is effected by tilting of lever56, and adjustment of said lever relative to said shoe may be. effectedb v simply shifting the pawl 57 with relation to the toothed segment 58.The front end ot shoe 51 is slightly rounded as seen in Fig. 6, and thesame is formed with a groove 51', as seen in Fig. 5. for engagement`with the string, the arrangement being such that, in the operation ofthe machine, the string will ride 1n the groove 51 and said presser shoewill constantly hold the same in engagement. with the cutting element.

In order to gage-the thickness or diameter of the string in the cuttingoperation, a shoe 63 is provided, the front end of which is adapted toengage withy the string before the same reaches the cutting element.Said shoe, as clearly seen in Figs. 4 and 6, is slidably mounted uponplate 46, the same being yieldingly held in its forward position bymeans of a leaf spring 64 which engages with a depending finger 65arovided at the rearward end of said shoe. he front end of said shoe isadapted to press the string against a eooperating shoe or guide 66, therearward end or shank 67 of which is adjustably secured tothe plate 45by means of a screw 68 which is threaded into an upstanding lug 69 atthe rearward end of said shank, said screw being rotatably adjustable ina lug 7 0 arising from plate 45. `A second screw 71 threaded into plate45 and engaging with an elongated slot 72 in portion 67 of said shoe,serves as additional means. of securing the same in position.

Reti-action of the shoe 63 is effected by means of a laterallyproject-ing arm 7 3 provided atthe rearward end of said shoe whichengages with a notch 74 provided in the adjacent Side of shoe 51, asseen in Fig. 6, the

arrangement being such that, upon retraction of shoe 51, shoe 63 will bealso simultaneously retracted.

Coperating with the shoe 63 is an arm 75 fulcrumed at 76 upon the upperside of plat-e` 52. Theparm 75 is formed with a shoulder 77 which isadapted for engagement a. post 78 arising from the rearward end of shoe63, a hehcal compression spring 79 interposed between lug 78" and a pinprovided upon said arm being adapted to normally hold the shoulder 77 inengagement with lug 78. The spring 79, however, 1s very light so thatthe same will not at all affect the operation of spring 64. The rearwardend of arm .75 is connected by means of a link 80 with lever 56, thelatter being pro vided with a pin '.81 which loosely engages with anelongated slot 82 formed in said link. The rearward end of arm 75 isbent toward the lever 56 so as to be adapted to serve `as a stop ashereinafter described.

The arrangement is such that, in the operation of the machine, when theoperator rocks the lever 56 to the right or in a direction to move thepresser shoe 51 toward the cutting element, that is in a direction topress the string into engagement with the cutting element, the shoe 63will move simultaneously with the shoe 51 under the influence of spring64. The forward end of shoe 51 is shghtly in advance of the shoe 63 andtherefore wlll contact with the string and press the same intoengagement with the cutting element before the shoe 63 has pressed thestring into engagement with the shoe or stop 66. When the latter occurs,however, movement of the shoe 63 will stop, the arm 75, having, in themeantime, been swung on pivot 76 by the lug 78 to ay certain position.`he operator will then continue to rock the arm 56 until the same justcontacts with the rearward end of arm 75, the latter thus serving as asort of guide or gage detei-mining the position of the shoe 51 and hencethe thickness of the cut taken on the string. The shoe 51 is held inthis position of adjustment simply through friction. By

reason of the shoe 63 being yieldingly'held in contact with the string,in the event of any bumps or other irregularities in the string, saidshoe will be adapted to yield rearwardly without affecting theadjustment of' shoe 51. The front end of shoe 63 and the adjacent sideof stop shoe 66 will be grooved to accommodate the string.

After the string has passed shoe 51 and the cutting element, the same isengagedby a guide 83the rearward end of which is adjustably secured b asclew 84 to plate 45, as clearly seen in Pigs. 4 and 6. The member 83 isalso grooved for engagement with the string. The members 66 and 83 willbe so positioned that in the passing of the string into engagement withthe front end of a shaft of shoer 51, the string will be required tobelly at the shoe 51, this arrangement of course resulting in cutting ofthe string simply at the place. of registration` therewith of the saidshoe 5l, inasmuch as the members 66 and 83 will serve to hold the stringaway from the/cutting element. Reciprocation of carriage 27 is effectedby means of a screw 85 rotatably mounted along one side of the bed ofthe machine, said screw being engageable by a split nut 86 of'conventional construction, which is oierable by a pivotally mountedarm`87. 'llhe arrangement is such that when the arm 87 is rocked to theright, as seen in Fig. l, the nut 86 engages with the screw 85, therebyestablishin an operative connection with said screw. vhen said arm isrocked to the left, said nut is expanded to disengage the screws.Coperating with said arm is a slidably mounted rod 87 adapted to be heldat its right hand terminal of movement or, in a position, as seen inFig. 1, by means of a keeper or pawl 88. Said rod is slidably mounted ina guide 89, between which and a collar 90 provided upon said rod isinterposed a helical compression spring 91 adapted, upon release of saidrod from keeper 88, to thrust the same to the left, in order to carryarm 87 to a position in which the split nut 86 will be moved to releasescrew 85. The keeper 88 is in the form of an armature with whichcoperates an electro-magnet 92, one side of which is grounded to themachine, the other side thereof being connected in a circuit 93 with acontact 94 provided upon the carriage. Secured to the frame of themachine adjacent the left hand.end thereof', is another contact 95 alsogrounded so that when thel contact 94 engages therewith, the circuitthrough electro-magnet 92 will be closed and said electro-magnetenergized, adapting the same to attract Vthe keeper 88 and thus releasethe rod 87. Thus, with this arrangement, it will be seen thata when thecarriage approaches its left hand terminal of movement an electricalconnection will be estab*L lished, which will automatically bring thecarriage to a stop, it being clear that upon movenient of keeper 88 toreleasing position, rod 87 will move under the influence of spring-91tofswing arm 87 to the left and hence to expand nut 86 from engagementwith screw 85.

Rotation of' screw 85 is effected by means 96 which, in the operation ofthe machine, will be continuously driven from asuitable source of power.through the medium of a belt 97 and pulley 98 provided upon said shaft.Loosely mounted upon shaft 96 are also pulleys 99 and 100 which areoperatively connected with the screw 85 by means of belts 101 and 102respectively, the belt 101 'being twisted as seen to obtain reverserotation of the screw. Operative connection between pulleys 99 and l100is effected through the medium of clutches 103 and 104 respectively,which are splined to shaft 96.` Shifting of clutches is effected bymeans of a reciprocatory rod 105 which carries shifting forks 106 and107 engaging respectively with said clutches 103 and 104. Thearrangement is such, that when one clutch is moved into operative po4sition the other clutch will be moved out and vice versa, thearrangement, further, being ,such that when clutch 104 is engaged,effecting driving of pulley 100, the screw 85 will be driven in adirection causing travel of carriage27 to the right, and when clutch 103is engaged causing rotation of pulley 99, rotation of the screw 85 willbe reversed, causing-return travel of carriage 27. The pulley on screw85 engaged by belt 101 is smaller than that engaged by belt 102, so thatreturn movement of the carria e will be at an increased speed. v

ctuation of rod 105 to effect the desired shifting of clutches 103 and104is secured through the medium of electro-magnets 108 and 109 withwhich coperates an amature l110 fixed to said rod,'said armature beinginterposed between said electro-magnets, as clearly seen in Fig. 1. `Oneside of the electromagnet 108 is connected by means of a conducto-r wire111 with a contact 1,12 on the frame of the machine, the other sideof'said electro-magnet being connected by means of a conductor wire 113with a contact 114 provided upon carriage 27. Similarly, one 'side ofelectro-magnet 109 is connected by means of a conductor wire 115 with acontact 116 on the frame of the machine, the other side of saidelectro-magnet being connected by means of a conducting wire 117 with acontact 118 provided upon carriage 27. The arrangement is such that -inthe travel of the carriage to the right, when the carriage reaches itsright hand terminal of movement, the contact v114 will engage withthecontaet 112, effecting closing of the circuit through electro-magnet108. Said magnet will then attract armature 110 causing automaticshifting of clutch 103 into operative position, thereby causing reversalof rotation of screw 85 wlth the conse uent return movement of thecarriage. hen said carriage reaches its left hand terminal of movementcontact 118 will engage with contact 116, thereby closing the circuitthrough electro-ma et 109, with theresult of causing shi ting of clutch104 into operative'position and with the result that rotation of screwv85 will be reversed, in order to adapt the same to drive the carriagein the opposite direction. Thus, it will be seen that the movements ofthe carriage will be automatically controlled.

Manual shifting 'of the carriage may be effected by the usual crankhandle 119 which is connected with a pinion 120 meshing with a rack 121provided at the underside of the bed of the machine.

In the. operation of the machine the operator brings the carriage firstto its left hand terminal of movement. The string to be aeted upon isknotted at both ends, one end being engaged with hook 19, the other endbeing passed between rollers 36 on jaws 35, thence through the sleeve ortube 41, being finally 'engaged with the hook 22. The weight 26 producesthe desired tension on the string, holding the same taut. Power is thenapplied to belt 13 which causes rotation of the string about itslongitudinal axis,as will be readily understood. The motor 28 is thenset into operation, after which the lever 56 is swung to the right tomove presser shoe 51 and cause the same to press the string intoengagement with the cutter. The position to which the presser shoe 51 isthus moved will be determined by arm 75 as above described. The operatorthen shifts the rod 87 to the right, engaging the same with keeper orpawl 88, thereby establishing connection between the carriage and thescrew 85, causing travel of the carriage along the bed of the machine tothe right. In this travel of the carriage the string is gradually cut ortrimmed, and as the end of the string is approached, the Contact 114engages with the r`contact 112 causing shifting of the clutch 103 intooperative position, with the result of automatically reversing thecarriage and carrying the same back to its initial position. lefore thisreverse is effected however, the outer endof the arm 56 will .be engagedby an adjustable stop member 122 carried by bearing 12 whichautomatically rocks lever 56 to the left thereby retracting shoe 51, andwith the result that the string will be held away from the cuttingelement by means of the guide members or shoes 66 and 83. When thecarriage reaches its left hand terminal of movement the contact 94 willengage with the contact 95, thereby causing release of rod 87 and withthe result of effecting automatic disenga ment of the carriage fromscrew 85. T is completes one cycle of operation, the string being thenremoved and another inserted in, its place to be similarly, treated. Inthe event of onel portion of the teeth of cutting element 34 becomingworn, the motor may be vertically adjusted through rotation of screw 32in order to present a fresh portion of the teeth of said cutter forcutting.

While I have illustrated and describe., the preferred form ofconstruction for carrying my invention into effect, this is capable ofVariation and modification without departing from the spirit of theinvention. I, therefore, do not wish to be limited to the precisedetails of construction Set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaims.

Having described my invention what l claim as new and desire to secureby Letters Patent is:

1. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a cutting elementarranged to contact with the string during rotation thereof; and meansfor effecting relative movement between said string and cutting elementin a direction longitudinally of the string, substantially as described.

2. A string ytruing machine comprising means for rotating a string aboutan axis extending longitudinally 'of the string; a cutting elementarranged to contact with the string during rotation thereof; vand meansfor effecting relative movementbetween said string and cutting elementat a uniform rate of speed in a direction longitudinally of the string,substantially as described.

A string truing machine comprising means for rotating a string about anaxis extending longitudinally of the string;a cutting element arrangedto contact with the string during rotation thereof; means for effectingrelative movement betweei said string and cutting element inl adirection longitudinally of the string; and means arranged adjacent tosaid cutting element adapted to embrace and rotate the string,substantially as described.

4.'A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a cutting elementarranged to contact with the string during rotation thereof; means foreffecting relative movement between said string and cutting `element ina direction longltu'dinally .of the string; and a pair of revolublymounted jaws arranged adjacent to said cutting element adapted toembrace and rotate the string, as described.

5. A lstring truing machine `comprising means forrotating a string aboutan axis extending longitudinally of the string; a v cutting elementarranged to contact with the string during rota'tion thereof; means foreffecting relative movement between said string and cutting element in adirection longitudinally of the string; and means arranged adjacent toand in fixed relation with said cutting element for rotating the string,substantially as described.

6. A string truing machine comprising means for rotatingthe end portionsof a string about an axls extending longitudi nally of the string; acutting element ar ranged to contact with the `string during `to contactwith tlie substantially v rotation thereof; and means adapted forengagement with the string intermediate the ends thereof and adjacentsaid cutting element for rotating the central portion of the string at aspeed the same as the speed of rotation of the ends thereof,substantially as described.

7. A string truing machine comprising means for rotating.,r the endportions of a string about an axis extending longitudiu nally of thestring; a cutting element movable longitudinally of the string adaptedstring during rotation of the latter: and means movable in unison withsaid cutting element adapted for engagement with the string intermediatethe ends thereof and adjacent said cutting element for rotating thecentral portion of the string at a speed of rotation the same as that ofthe ends of the string. substan- 4tially as described.

8. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a cutting elementarranged to contact with the string during rotation of the latter; meansfor effecting relative movement of said stringand cutting element in adirection longitudinally of the string; and means for holding the stringin engagement with said cutting element, substantially as described 9. Astring truing machine comprising means for rotating a string about anaxis extending longitudinally of the string; a cutting element, arrangedto contact with the string during rotation of the latter; means foreffecting relative movement of said` string and cutting element inI adirection longitudinally of the string; and means adjustable toward andfrom said cutting element for holding the string in engagement with saidcutting element, substantially as described.

l0. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a cutting elementarranged to contact with the string during rotation of the latter; meansfor effecting relative vmovement of said string and cutting element in adirection longitudinally of the string; means adjustable toward and fromsaid cuttingelement forholding the string in engagement with saidcutting element; and means adapted for engagement with the string beingacted upon for determining the position of said holding means,substantially as described.

11. A string truing machine compri-sing means for rotating astring-about an axis extending longitudinally of the string; a cuttingelement arranged to contact with said string and cutting element in adirection longitudinally of the string; means adjustable toward and fromsaid cutting element for holding the string in engagement with saidcutting element; and -manually operable means adapted for engagementWith the string being acted upon for determining the position of saidholding means, substantially as described.

12. A Jstring truing machine comprising means for stretching a stringtaut and rotating the same about an axis extending longitudinally of thestring; a cutting element arranged to contact with the string duringrotation of the latter; and means for moving said string and cuttingelement relatively to each other in a direction longitudinally of thestring, substantially as described.

13. A string truing machine comprising means for exerting a pull, on astring to stretch the same taut; means for rotating the string about anaxis extending longitudinally of the string; a cutting element adaptedfor engagement with the string during rotation of the latter; and meansfor moving said string and cutting element relatively to each other in adirection longitudinally of the string, substantially as described.

14. A string truing machine comprising means for rotating a string aboutan axis extending llongitudinally of the string; a carria-ge mountedpformovement longitudinally of the string; a cutting element carried by saidcarriage for lcontact with the string;

and means for moving-said carriage, sub-l stantially as described.

1 5. A string truing machine comprising means for rotating the endportions of'a string about an axis. extending longitudinally of thestring; acarriage mounted for movement longitudinally of the string; acutting element carried by said carriage for contact with the string;and means on said carriage `adjacent ysaid cutting element for Aclampingthe centralj portion of the string and rotating the same at a speed thesame as the speed of rotation of the ends of thestring, substantially asdescribed.

16. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a carriage mounted forreciprocatory movement in a direction longitudinally of the string; acutting element carried by said carriage for contact with the string;means for moving said carriage; and means for automatically reversingthe direction of movement of said carriage, substantially as described.

17. A string truingl machine. comprising means for V,rotating a stringabout an axis extending longitudinally'of the string; a carriage mounted`for reciprocatory movement`in a' direction longitudinally of thestring; a cutting element carried by said carriage for contact with thestring; means for moving said carriage; means for automaticallyreversing the direction of movement ot said carriage when the carriagereaches one terminal of its movement; and means for automaticallystopping said carriage when the same reaches its other terminal ofmovement, substantially as described.

18. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a carriage mounted forreciprocatory movement in a direction longitudinally of the string; acutting element carried by said carriage for contact with the string;means for moving said carriage; means for alitomatically reversing thedirection of Inovement of said carriage; means for holding the string incontact with said cutting element during movement of the carriage in onedirection; and means for holding the string out of contact with saidcutting element `during movement of the carriage in the oppositedirection, substantially as described.

19. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a carriage mounted forreciprocatory movement in a direction longitudinally of the string; acutting element carried by said carriage for contact with the string;means for moving said carriage; means for automatically reversing thedirection of movement of sai(l carriage; means for pressing the stringinto contact with said cutting element during the movement of thecarriage in one direction: and means 'for automatically retracting saidstring pressing means upon said carriage reaching one terminal of itsmovement, substantially as described.

20. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a carriage mounted forreciprocatory movement in a direction longitudinally of the string; acutting element carried by said carriage for contact with the string;means for moving said carria e; means' for automatically reversing thedlrection of movement of said carriage; means for pressing the stringinto contact with said cutting element during the movement of thecarriage in one direction; means for automatically retracting saidstring pressing means upon said carriage reaching one terminal of itsmovement; and means for holding the string out of contact with saidcutting element during movement of the carriage in the o ipositedirection, substantially as described.

21. A stringtruing machine comprising means for rotating a string aboutan axis extending longitudinallymof the string: and a rotary cuttingelement arranged to conlil tact with the string during rotation of thelatter, substantially as described.

22. A string truing machine comprising means for 'rotating a stringabout an axis extending longitudinally of the string; and a rotarycuttlng element7 said cutting element having teeth upon one of thetransverse faces thereof adapted to contact with the strin duringrotation of the latter, substantially as described.

23. A string' truing machine comprising means for rotating a stringabout an axis ex tending longitudinally of the string; and a rotarycutting element, said cutting element having radial teeth upon one ofthe transverse faces thereof adapted to contact with the string duringrotation of the latter, substantially as described.

24. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a cutting e ementarranged to contact with the string during rotation of the latter; meansfor effecting relative movement between said string and cutting elementin a direction longitudinally of the string; and a shiftably mountedshoe having a groove in one end adapted for engagement with the stringforholding the same in contact with said cutting element, substantiallyas described.

25. A string truing machine comprising means for rotating a string aboutan axis extendinaF longitudinally of the string; a cutting 'elementarran ed to Contact with the string during rotation of the latter; meansfor effecting relative movement of said acted upon for determining`string and cutting element in a direction longitudinally of the string;means adjustable toward and from said cutting element for holdingthestring inv engagement with said cutting element; and means adapted foryieldable engagement with the string being the position of said holdingmeans, substantially as described.

26. A string truing machine comprising means for rotating a string aboutan axis extending longitudinally of the string; a cutting elementarranged to contact with the string during rotation of the latter; meansfor effecting relative movement of said string and cutting element in adirection longitudinally of the string; means for holding the string inengagement with said cutting element; and Imeans for guiding the stringto avoid contact with said cutting element except yat the place ofregistration therewith of said holding means, substantially asdescribed.

27. The process of truing a string which consists in rotating the stringabout its longitudinal axis with the same stretched taut and applying acutting element to the string during the rotation thereof, substantiallyas described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

GEO. NQ EINsELE.

Witnesses:

ARTHUR A. OLSON, JOSHUA R. H. Porrs.

